Figure 6.

Effect of Al application (90 μm Al_mono in agarose gel) for 1 h to specific root zones on the root surface (distance 20 μm) pH profiles along the primary roots of the maize cv ATP-Y (●; Al-resistant) and cv Lixis (○; Al-sensitive). The pH of the bulk solution containing KCl and CaCl₂ at 200 μm was adjusted to 4.5. Values are means of three independent replicates ± sd. The results shown are representative of three independent experiments. The shaded areas indicate the zone of Al application.